Web Inspector: MainScriptMapping should detect snippet scripts by means of sourceURL...

Web Inspector: MainScriptMapping should detect snippet scripts by means of sourceURL set before evaluation.
https://bugs.webkit.org/show_bug.cgi?id=81031

Reviewed by Pavel Feldman.

Source/WebCore:

* inspector/front-end/SnippetsModel.js:
(WebInspector.SnippetsModel):
(WebInspector.SnippetsModel.prototype._saveSettings):
(WebInspector.SnippetsModel.prototype.deleteSnippet):
(WebInspector.SnippetsModel.prototype._snippetAdded):
(WebInspector.SnippetsModel.prototype._sourceURLForSnippet):
(WebInspector.SnippetsModel.prototype.snippetIdForSourceURL):
(WebInspector.SnippetsModel.prototype.snippetForSourceURL):
(WebInspector.Snippet.prototype.evaluate):
(WebInspector.SnippetsScriptMapping):
(WebInspector.SnippetsScriptMapping.prototype.uiLocationToRawLocation.get if):
(WebInspector.SnippetsScriptMapping.prototype.uiLocationToRawLocation):
(WebInspector.SnippetsScriptMapping.prototype._releasedUISourceCodes):
(WebInspector.SnippetsScriptMapping.prototype._snippetAdded):
(WebInspector.SnippetsScriptMapping.prototype._snippetWillBeEvaluated):
(WebInspector.SnippetsScriptMapping.prototype._snippetRemoved.get this):
(WebInspector.SnippetsScriptMapping.prototype._snippetRemoved):

LayoutTests:

* inspector/debugger/snippets-model-expected.txt:
* inspector/debugger/snippets-model.html:

git-svn-id: http://svn.webkit.org/repository/webkit/trunk@110864 268f45cc-cd09-0410-ab3c-d52691b4dbfc